Although considerations have been given in the past to the need for anti-aging agents, since the mechanism and definition of aging have not been clarified, aging has typically been assessed by measuring moisture retention or skin resiliency as indicators of skin moistness or by visually observing skin color. However, research on aging has progressed in recent years, and age has been determined to be an important factor as a cause of skin aging in macroscopic terms, while the effects of drying, oxidation and sunlight (ultraviolet rays) and the like have also been indicated to be direct factors involved in skin aging. Known examples of specific phenomena associated with skin aging include reductions in collagen and elastin levels in the dermis, reductions in the levels of hyaluronic acid and other mucopolysaccharides, and cell damage caused by ultraviolet rays. Among these, although elastin contributes to tissue resiliency by mutually forming crosslinks, denaturation and destruction of elastin by excess expression of elastase, an enzyme that breaks down elastin, caused by exposure to ultraviolet rays and aging is thought to lead to a decrease in skin resiliency. Thus, inhibiting the action of elastase and preventing denaturation and destruction of elastin to impart resiliency and tightness to skin are important for preventing skin aging.
Although natural ingredients are preferable in the case of cosmetics and the like that are applied directly to the skin, known examples of natural elastase inhibitors include Ficus religiosa extract (Patent Document 1), Saxifraga sarmentosa extract (Patent Document 2), Uncaria gambir extract of the Madder family (Patent Document 3) and Rhododendron simsii extract of the Heath family (Patent Document 4), and external skin preparations containing these extracts have been shown to demonstrate improvement effects on wrinkles, fine wrinkles and in terms of skin tightness and sagging.
On the other hand, elastase inhibitors are also known to be useful in the treatment of disease in addition to their use as external skin preparations, and have been reported to be effective against diseases such as joint diseases including chronic rheumatoid arthritis and osteoarthritis, systemic inflammatory response syndrome, arteriosclerosis, acute lung disorders or acute respiratory distress syndrome.
Specific examples of such elastase inhibitors include pharmaceuticals such as urinary trypsin inhibitor, which is used for acute pancreatitis or acute circulatory failure (hemorrhagic shock), and the selective neutrophil elastase inhibitor, sivelestat sodium, which is effective for improving acute lung disorders associated with systemic inflammatory response syndrome. In this manner, although elastase inhibitors are used as therapeutics for the treatment of inflammatory diseases and the like, in consideration of safety, products composed mainly of natural ingredients rather than synthetic chemicals are preferable in this case as well.
Prior Art Documents
Patent Publications
Patent Document 1: Japanese Unexamined Patent Publication No. H11-335230
Patent Document 2: Japanese Unexamined Patent Publication No. H11-246386
Patent Document 3: Japanese Unexamined Patent Publication No. H10-182414
Patent Document 4: Japanese Unexamined Patent Publication No. 2009-191043